Clearing Blocked Plumbing Vents the Right Way
Among the many parts of a plumbing system, the vents are the most overlooked, despite being one of the most important. They permit the entry of air into the structure’s drain system, and when clogged, you will feel the effects in an instant. Every plumbing drain in the home (as well as every toilet) has a vent pipe which connects to the primary stack that goes through the roof so when a blockage needs to be cleared, start there.
Signs of a Blocked Vent
When vents are blocked, any water that flows creates suction. This, in turn, causes the following:
- Drains move slower
- Drains clog more often
- Gurgling from a fixture when water goes down another fixture—this happens when air gets sucked right through the trap of the fixture that gurgles.
- Smells coming from the sewer. These happen when suction is so strong that it can drain water from the trap of at least one fixture.
Vent System Structure
The collection of vents and drains in a home is called the DWV or drain-waste-vent system. All drains of a home flow to a single sewer while every vent rises to connect with a common inlet known as the vent stack. Just like a drain, a vent needs to keep a net slope to the sewer, with respect to the primary stack. This is usually found above one of the bathrooms. A lot of vent blockages happen at the primary stack, although there is a chance that the vent of only one fixture is blocked. This happens more often with wet vents, vents which also function as drains.
How to Clear the Main Stack
Debris, leaves, and small animals can block the main stack. Do the following steps to clear it:
- Clear the opening of the vent
Clear out visible debris after wearing a pair of gloves. Check the interior of the stack—a bird’s nest or a few small animals might be stuck there.
- Spray water down the vent
With a garden hose, clear blockages located deep in the vent which you cannot reach by hand. In numerous instances, the water should flush the pipe clean, but if the clog is in a bend, expect water to overflow.
- Get a drain snake and use it to remove obstructions
Insert a sewer snake (a lengthy plumbing snake you can buy or rent) down the opening of the vent. Feed its entire length slowly, if needed, in order for its cutting head to be able to break obstructions.
How to Deal with Snow and Ice Correctly
It is not safe to scale the roof during the winter, but fortunately, it is often not necessary if you need to clear snow and ice from vents. Instead, head to the attic. Once you’re there, find the vent pipe and, with a hairdryer, heat the part nearest the roof. If vents are often blocked, you might prefer to insulate that portion of pipe or replace the stack with a pipe with a wider diameter.